The air flow in HVAC ducts in buildings is typically controlled by dampers. Dampers have a number of vanes that open and close and are placed in the air stream of the ducts to control the air flow. Dampers generally have a round shaft that is connected to the vanes. Rotating the shaft controls the position of the vanes to control the flow of air through the damper. Typically, the shaft is rotated approximately ninety degrees in one direction to open the damper and approximately ninety degrees in the opposite direction to close the damper. A damper actuator is used to rotate the shaft to open and close the damper. Damper actuators are typically electrically powered motorized devices that are connected to an HVAC control system. The HVAC control system sends electrical signals to the actuators to control the position of the dampers. Examples of damper actuators include M9206 Series and M9216 Series electric spring return actuators manufactured and sold by Johnson Controls, Inc.
A damper actuator generally has a housing with a hollow hub extending therethrough. A coupling device is provided to couple a damper shaft to the hub, allowing for damper shafts of differing sizes to be utilized with the same internal hub diameter. The hub is rotated by a motor to rotate the damper shaft, thus controlling the position of the damper. When the actuator is directly mounted to and typically supported by the damper shaft, the actuator is considered to be direct coupled to the damper shaft.
Conventional direct coupled actuators are typically installed by inserting a free end of the damper shaft through the hub and housing. Because an end of the shaft is inserted into or removed from the hub during installation or removal of the actuator, the actuator may be referred to as an end-mount actuator.
In very large ducts, multiple dampers are arranged side-by-side and above and below each other, typically with a shaft running through a row of several dampers. Mounting an end-mount direct coupled actuator between two dampers in a such a large duct situation requires that the shaft be threaded out of the dampers, the actuator properly mounted, and the shaft replaced. It is therefore difficult to service or replace an end-mount direct coupled actuator in a large duct because of the difficulty in removing the direct coupled actuator from the shaft.
It would be advantageous for a direct coupled damper actuator to be configured to be mounted to a damper shaft without requiring the removal or displacement of the damper shaft. Further, because direct coupled actuators are used in the majority of HVAC applications, it would be advantageous to provide a damper actuator system allowing a damper actuator to be utilized in either a end-mount fashion or in a configuration that does not require remount or displacement of the damper shaft during installation or removal.
It would be desirable to provide a system and/or method that provides one or more of these or other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed herein extend to those embodiments that fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.